1. Field of the Invention
The present invention relates to a semiconductor device having an isolation layer that physically and electrically isolates semiconductor elements such as transistors, resistors and the like.
2. Description of the Related Art
Such isolation layers have heretofore been formed to have a flat configuration on flat regions. As shown in FIG. 6, for instance, isolation layer regions 63 and impurity diffusion layer regions 64 are formed in the same plane of the surface of the semiconductor substrate 61, each isolation layer region 63 having a predetermined distance and area. Inversion protection layer regions 62 may be formed beneath isolation layer regions 63. A semiconductor circuit component is formed in each region 64.
Microminiaturization and high-density integration of a semiconductor device have been difficult because the isolation regions require the predetermined distance and area.